Digital dermatoscopy is used to capture accurately the time-dependent growth of dermal neurofibromas and cafe-au-lait macules and patches on the skin of NF1 patients. Sequential images of lesions on patients and associated biopsies have been performed on pediatric and adult patients. In 2008, the addition of pediatric patients to this project was accomplished. As the study progesses, we anticipate obtaining quantitative information about the rate of lesion development and change in both the pediatric and adult NF1 population. Additionally, we have begun a study of the cutaneous manifestations of Cowden syndrome. The spectrum of cutaneous findings associated with this genetic condition of germline PTEN is being re-evaluated in patients recruited for a trial of sirolimus therapy. Select cutaneous lesions are imaged dermatoscopically to determine their responsiveness to sirolimus therapy. To date 16 patients have entered this study.